Incandescent lamp and fixture



1966 E. E. KENDALL ETAL 3,267,275

INCANDESCENT LAMP AND FIXTURE Filed Nov. 29, 1963 ERNEST E. KENDALLROBERT J, M INTYRE INVENTORS FIG.3

AT RNEY Patented August 1%, liinifi 3,267,275 INCANDESCENT LAMP ANDFEXTURE Ernest E. Kendall, Peabody, and Robert .l. Mclntyre,

Gloucester, Mass, assignors to Sylvania Electric Products Inc., acorporation of Delaware Filed Nov. 29, 1963, Ser. No. 326,36) 6 Claims.(Cl. 24tlll.2)

This invention relates to tubular type incandescent lamps andparticularly to positioning of such lamps in a fixed and vibration-freeposition.

Tubular type incandescent lamps are known to the art, however, the typeto which our invention has particular applicability is the so-calledquartz-iodine lamp in which a tungsten filament is axially disposedwithin a tubular, quartz envelope containing iodine.

Heretofore when electrical connections for such lamps were made, it wascommon practice to slip slotted, cylindrical, refractory sleeves aroundpress seals formed at the ends of the envelope. Cements were then usedto secure the sleeve to the glass. The outward ends were fitted withsocket-type electrical contacts and cooperating springbiased, balljoints were used in the fixture.

We have now found that in installations where the lamps are subjected tohigh impact and shock forces, that such fixtures and lamp fittings arenot wholly satisfactory. The lamp can rotate about its axis in thefixture and sometimes become dislodged. Because of a residual exhausttube tip, such rotation can change the lamps lighting characteristics.Frequently the combination of vibration and rotation can cause thecement which holds the sleeve on the seal to crack and such cracking canbreak the electrical connection. Furthermore when the ball andsocket-type construction was used in outdoor installations, oxidationsometimes ruined the electrical connection between the fixture and thelamp.

According to our invention, we dispose a hollow, cylindrical metalconnector having a slotted end on each of the press seals. The connectoris anchored to the seal by extending the lamps lead in wires through thebase and soldering them to the metal. Preferably the entire connector isfilled with solder to add permanence to the structure. A groove ismachined into each of the cylindrical connectors so that rotation-freepositioning will be assured in the fixture. The fixture in which thelamp is placed includes a spaced pair of opposing spring clips, each ofthe clips having a detent formed on one of the legs.

Accordingly, the primary object of our invention is rotation-free anduniform mounting of tubular incandes cent lamps in fixtures.

The many other objects, features and advantages of our invention willbecome manifest to those conversant with the art upon reading thefollowing specification when taken in conjunction with the accompanyingdrawings wherein preferred embodiments of our invention are shown anddescribed.

Of these drawings:

' FIGURE 1 is a top plan view of the lamp fixture with the tubularincandescent lamp disposed therein.

FIGURE 2 is a front elevational view of the fixture and lamp shown inFIGURE 1 with a portion of the lamp and the fixture cut away.

FIGURE 3 is an enlarged cross-sectional view, taken along the line 3-3of FIGURE 2, illustrating the relationship of the lamp in the fixture.

Referring noW to FIGURE 1 of the drawing, the lamp 1 comprises atubular, quartz glass envelope with an incandescent filament 2 disposedaxially therein. Usually the filament is supported upon lead-in wires 3and 4- which are connected through press-seals 5 and 6 to the power linethrough the intermediary of the fixture elements.

Enclosed within the envelope is a fill including a quantity of iodineand hence, the lamps are called iodine-quartz lamps.

Incandescent lamps having quantities of iodine in the envelope are knownto the art. Such lamps operate on a tungsten-iodine cycle which is aregenerative, continuing process in which tungsten iodine is producedwhen the iodine combines chemically with particles of tungstenevaporating from an incandescing tungsten filament. Subsequent thermaldecomposition of this compound replaces the tungsten particles on thefilament. In conventional filament lamps not containing controlledquantities of iodine, these particles are deposited on the envelope,thus generally causing a loss of light output due to blacle eningjRupturing of the filament may occur when a suflicient quantity oftungsten particles evaporates and the lamp must be replaced. However,the iodine-tungsten cycle eliminates lamp blackening and reduces lampoutage by its getter action.

The iodine, together with the heat of the lamp, prevents the tungstenfrom accumulating on the lamp envelope and darkening it. As thevaporized tungsten iodide circulates back into the area of theincandescent filament, the intense heat of the filament frees thetungsten from the tungsten iodide by thermal decomposition and thistungsten is deposited back on the filament leaving the iodine free tobegin a new cycle. Theoretically, if the evaporating tungsten particlescould be returned to the filament in a perfectly even coating, the lampmight never burn out. But since there is no way to control exactly wherethe tungsten particles return to the filament, one spot will eventuallywear out, thus rendering the iodinequartz lamp inoperative. Thiscondition, however, occurs after operation in the order of hundreds ofhours and possibly even thousands of hours before lamp failure.Furthermore, during the life of an iodine lamp, the maintenance of lightoutput is substantially constant.

The press-seals 5 and 6 are formed by heating the ends of the tubularquartz envelope while the lead-in wires attached to the filament 2 aredisposed therethrough.

Although not shown in this figure, the lead-in wires have anintermediary molybdenum foil section welded thereto so that a tightmetal to glass seal can be made. When the glass is sufficiently plastic,the walls are pressed together and allowed to cool. The seal which isformed is fiat and is preferably designed to have raised or thickenededges which makes the envelope more resistant to breakage. Furthermorethe use of thickened edges can help to prevent lateral movement of thelamps electrical contact.

Slipped over each of the press seals 5 and 6 and b tween the thickenededges, are cylindrical metal connectors 7 and 8 which are attached tothe lead-in wires 3 and 4 respectively. Preferably the diameter of thecylinder is substantially equal to the width of the flat portions of thepress seal between the raised edges. The hollow cylindrical connectorshave slots on each side thereof, so as to form legs which mayconveniently fit of each side of the seal. Preferably the width of theslot is just slightly greater than the thickness of the fiat portion ofthe seal so that the assembly can be made rugged.

The cylindrical connectors 7 and 8 are pressed into the resilient clipswhich are formed in a general U-shape, the legs of the U being springbiased towards each other. Each of the legs are recessed inwardly andthen bent outwardly to form a cylindrically shaped retaining portionwhich has the same general shape as the cylindrical connectors 7 and 8.Preferably the tops of the clips are flared outwardly so that the lampmay be easily seated.

According to our invention, we form grooves 9 and having generally flatinner surfaces in each of the cylindrical contact elements, usually onopposite sides thereof. On each of the spring clips we form detents 11and 12 into which the grooves will compatably fit. The use of the grooveand detents will prevent rotation of the lamp in the fixture. Thegrooves are sufficiently wide that the detents will fit into them andthe spring clips will snap closed and tightly fit around the connectors.

If the grooves are placed on opposite sides of the respective cylindersand the cooperating detents formed on the clips accordingly, uniformdisposition of the contacts in the fixtures can always be attained andthe bottom of the lamp can always be pointed downwardly.

The fixture upon which the lamp is mounted may be of any desired shapehowever we prefer to dispose a button-type fuse 13 between a pair ofleaf-type springs 14 and 15 so that if the lamp should fail, the fuse 13will prevent short-circuiting. Electrical connections can be made at anyconvenient location upon the body of the fixture.

Referring now to FIGURE 2, the press-seals and 6 are shown with thelead-in wire assembly. The assembly includes the internal lead-in wires3 and which extend into the envelope and have the ends of the filament 2disposed thereon. As has been described briefly, welded to the lead-inwires are thin molybdenum foil sections 17 and 18 which in turn areconnected to external lead-in wires 19 and 22, the latter extendingoutside of the lamp. We prefer to use the above-described lead-in wireassembly because when cool, the quartz forms a tight seal about themolybdenum sections 17 and 18 and will not scale or break away.

As shown in the broken away section, the detent 11 extends inwardly intothe generally cylindrical portion of the spring clip. The exact width ofthe detents is not critical so long as they are wide enough to supportthe lamp without bending and will fit into the corresponding groove ofthe connector.

When mounting the cyindrical connectors 7 and 8 upon the press seals 5and 6, we extend the external lead-in wires through the middle of thecylinder and then fill in the ends with solder, lead or similar metals.When the filling is hard, the connectors 7 and 8 will be firmly attachedby the legs on each of the press-seals and also anchored by the lead-inwires.

Through the use of a lamp having grooved connectors and a fixture withcorresponding detents, the lamp can always be positioned uniformly withthe exhaust tu-be tip 21 pointed downwardly where it cannot effect thelight distribution pattern of the lamp.

Frequently as a further support, we dab small quantities of hightemperature cement upon the press-seals so that even greater rigidity isobtained. After the legs of the cylindrical connectors are slipped overthe press seals, the cement will harden, act as a filler and prevent anymovement whatsoever.

As seen in FIGURE 3, the cylindrical connectors have a groove 9 intowhich fits detent 12 of the U-shaped clip. The remainder of the clampingportion or the U-shaped clip is cylindrically shaped to conform to theshape of the connector.

Lead-in wire 22 is disposed within the cylindrical connector 8 andpreferably, although not necessarily, rests upon one of the walls toprovide a better electrical connection. The cylinder is filled withlead, solder or similar metal 20 to insure permanence. Of course, it isequally possible to reduce the internal diameter of the cylinder to apoint where the bore is just slightly larger than the external lead-inwire 22 and then spot weld the lead-in wire to the mouth of the hole.

It is apparent that many changes and modifications can be made withinthe spirit and scope of the instant invention but it is our intention,however, only to be limited by the spirit and scope of the appendedclaims.

As our invention we claim:

1. An incandescent lamp comprising: a tubular glass envelope having fiatseals disposed at either end thereof; a filament disposed within saidenvelope; means to conduct current from outside of said envelope intosaid filament, said means including lead-in wires extending outwardlyfrom said seals; a generally cylindrical metal connector disposed at oneend of said sealed envelope and a second generally cylindrical metalconnector disposed at the other end thereof, each of said connectorshaving slots into which said press seals fit; a groove formed in each ofsaid first and second connectors and disposed on opposite sides thereof;said lead-in wires extending inside of said cylinders and attachedthereto and in electrical conducting relationship therewith.

2. The lamp according to claim 1 wherein each of the cylindricalconnectors are hollow and said lead-in wires extend therethrough, theconnectors being filled with a metal to secure the electrical connectorand prevent relative movement.

3. The lamp according to claim 1 wherein said press seal has thickenededges and legs formed in said connectors are disposed directly upon theflat, central portion of said seal and between the thickened edges.

4. Incandescent lighting equipment comprising: a pair of spaced apart,U-shaped, spring biased clips, a portion of each of said clips having agenerally cylindrical shape; a detent formed in each of said clips; anincandescent lamp comprising a tubular glass envelope having flat sealsdisposed at either end thereof; a filament disposed within saidenvelope; means to conduct current from said clips into said filament,said means including lead-in wires extending outwardly from said seals;generally cylindrical metal connectors disposed at either end of saidsealed envelope, said connectors having slots into which said pressseals fit, said slots forming legs in said connector; a groove formed ineach of said cylindrical connectors and disposed on opposite sidesthereof; said lead-in wires extending inside of said cylinders and inelectrical conducting relationship therewith; a groove formed on each ofsaid connectors; said detents being disposed in said grooves and therest of the cylindrical portion of said clip being disposed about saidconnectors.

5. The equipment according to claim 4 wherein each of the cylindricalcontainers are hollow and said lead-in wires extend therethrough, theconnectors being filled with a metal to secure the electrical connectionand prevent relative movement.

6. The equipment according to claim 4 wherein the press seals of saidlamp have thickened edges and said legs of said connectors are disposeddirectly upon the fiat central portion of said seal and between thethickened edges.

References Cited by the Examiner UNITED STATES PATENTS 1,909,632 5/1933Prouty 33950 3,001,096 9/1961 Mosby 313318 3,001,097 9/1961 Smialek3l33l8 3,156,841 11/1964 Ayres 313-318 X NORTON ANSHER, PrimaryExaminer.

C. R. RHODES, Assistant Examiner.

1. AN INCANDESCENT LAMP COMPRISING: A TUBULAR GLASS ENVELOPE HAVING FLATSEALS DISPOSED AT EITHER END THEREOF; A FILAMENT DISPOSED WITHIN THEENVELOPE; MEANS TO CONDUCT CURRENT FROM OUTSIDE OF SAID ENVELOPE INTOSAID FILAMENT, SAID MEANS INCLUDING LEAD-IN WIRES EXTENDING OUTWARDLYFROM SAID SEALS; A GENERALLY CYLINDRICAL METAL CONNECTOR DISPOSED AT ONEEND OF SAID SEALED ENVELOPE AND A SECOND GENERALLY CYLINDRICAL METALCONNECTOR DISPOSED AT THE OTHER END THEREOF, EACH OF SAID CONNECTORSHAVING SLOTS INTO WHICH SAID PRESS SEALS FIT; A GROOVE FORMED IN EACH OFSAID FIRST AND SECOND CONNECTORS AND DISPOSED ON OPPOSITE SIDE THEREOF;SAID LEAD-IN WIRES EXTENDING INSIDE OF SAID CYLINDERS AND ATTACHEDTHERETO AND IN ELECTRICAL CONDUCTING RELATIONSHIP THEREWITH.